What is liquefaction factor?
Liquefaction is a phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading. Liquefaction occurs in saturated soils, that is, soils in which the space between individual particles is completely filled with water.
What factors influence liquefaction potential?
Influence factors and Control methods Some factors that influence liquefaction were considered such as initial shear stress, consolidation pressure, particle composition, dry density, and soil structure.
How do you reduce liquefaction?
The most common way of preventing the occurrence of liquefaction are foundation soil improvement methods. One type of improvement is to replace the susceptible soil with the appropriate amount of gravel. A more favourable form of the granulometric soil curve in a narrower location is obtained in this way.
How do you calculate liquefaction potential?
The potential for liquefaction is then described in terms of a factor of safety against liquefaction, FSL = CRR/CSR. If the factor of safety is less than one, i.e., if the loading exceeds the resistance, liquefaction is expected to be triggered.
What causes liquefaction?
Liquefaction occurs when vibrations or water pressure within a mass of soil cause the soil particles to lose contact with one another. This condition is usually temporary and is most often caused by an earthquake vibrating water-saturated fill or unconsolidated soil.
How can the effects of liquefaction be reduced when building structures?
If it is necessary to construct on liquefaction susceptible soil because of space restrictions, favorable location, or other reasons, it may be possible to make the structure liquefaction resistant by designing the foundation elements to resist the effects of liquefaction.
Which type of rock is most susceptible to soil liquefaction?
Poorly drained fine-grained soils such as sandy, silty, and gravelly soils are the most susceptible to liquefaction.
How does liquefaction occur?
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes.
What is factor of safety against liquefaction?
The most common approach used to forecast liquefaction triggering is the factor of safety against liquefaction (FS), which is defined as the cyclic resistance to cyclic stress ratio for a layer of soil at depth, z (Seed and Idriss, 1971).
What causes static liquefaction?
1, static liquefaction is triggered in a saturated loose cohesionless soil by a monotonically-increasing shear load (e.g., raising the embankment height, oversteepening, the slope, toe erosion, rapid sediment accumulation, construction loading, weight of the construction/repair equipment, tidal changes, reservoir …
What is the cause and effect of liquefaction?
Liquefaction of soil causes structural instability in buildings. This occurs due to various instances of structural failure. The liquefied ground cannot sustain the stresses of its load from the foundations. Foundations will sink into the sand deposit and cause the building to lean and eventually collapse.